My 2016 A5 2.0 Sportback (2007-2016 model) has developed an Adblue fault that reads “Adblue: system fault. No restart in 600 miles! See owner’s manual”.

The adblue tank has been topped up to full (took approx 5 litres to fill to full) and I have driven the car a few times and added around 50 miles, to allow time for the adblue level sensor to reset. We also drained 0.5 litres of adblue in case I’d over filled it.

My mates OBD reader shows error code P20E8, which when deleted, immediately returns.

I tried disconnecting the adblue pipe in the engine bay, but noticed that after 2 mins 40 seconds, the flow of adblue stops. Approx 1 litre is pumped out before stopping. This was repeated twice, with the same result.

I then tried the old Ctrl-alt-delete and disconnected the car battery for 20 minutes to allow the car to reset, deleting the fault before disconnecting. After 20 minutes, I then reconnected everything. The fault immediately returned. I then took the car for a 15 min drive to make sure the engine was hot. At the end, with the engine still running, I disconnected the adblue pipe in the engine bay and nothing was being pumped out. Is this right, or is it a failure of the adblue pump? I now have 550 miles to “No Restart”. 😱 Cheers!

Edited July 24, 20232 yr by djjmorgan
Extra detail added

Adblue faults are common it's often the sensor or the module that fails. 

Did you manage to get this sorted, I had my ad blue injector and cap replaced but still comes up with fault, please let me know.

Common issues is crystallized addblue floater, stuck. You can try remove the whole tank and just clean it up. Next can be low pressure pump and injector.  Go to garage and let them find the problem.

You won't get an answer from dominic, he has not bothered to return to the forum since posting his question.

Search recent forum history and you will find similar topics with a lot of useful information.

On 7/24/2023 at 9:53 PM, djjmorgan said:

My 2016 A5 2.0 Sportback (2007-2016 model) has developed an Adblue fault that reads “Adblue: system fault. No restart in 600 miles! See owner’s manual”.

The adblue tank has been topped up to full (took approx 5 litres to fill to full) and I have driven the car a few times and added around 50 miles, to allow time for the adblue level sensor to reset. We also drained 0.5 litres of adblue in case I’d over filled it.

My mates OBD reader shows error code P20E8, which when deleted, immediately returns.

I tried disconnecting the adblue pipe in the engine bay, but noticed that after 2 mins 40 seconds, the flow of adblue stops. Approx 1 litre is pumped out before stopping. This was repeated twice, with the same result.

I then tried the old Ctrl-alt-delete and disconnected the car battery for 20 minutes to allow the car to reset, deleting the fault before disconnecting. After 20 minutes, I then reconnected everything. The fault immediately returned. I then took the car for a 15 min drive to make sure the engine was hot. At the end, with the engine still running, I disconnected the adblue pipe in the engine bay and nothing was being pumped out. Is this right, or is it a failure of the adblue pump? I now have 550 miles to “No Restart”. 😱 Cheers!

I have literally had the same issue this past week (exact same make and model ) Garage has stated fuel injector pump fault which has set me back £643+VAT - I could cry, can't put it off as the car will cease to start in 500 miles 

1 hour ago, LaylaD said:

I have literally had the same issue this past week (exact same make and model ) Garage has stated fuel injector pump fault which has set me back £643+VAT - I could cry, can't put it off as the car will cease to start in 500 miles 

The fuel injector pump? Surely they mean the Adblue pump.